the economic theories of gingrich, santorum, and romney. they are bankrupt. if you give any one of these guys the keys to the white house, they will bankrupt the middle class again. >> the vice president focused specifically on the government's rescue of the auto industry. biden says that never would have happened if the president's opponents had their way. it saved a million jobs. >> governor romney was more direct. let detroit go bankrupt. newt gingrich said, quote, a mistake. but the guy i work with every day, the president, he didn't flinch. this is a man with steel in his spine. he made the tough call and the verdict is in. president obama was right and they were dead wrong. >> president obama himself, meanwhile in maryland yesterday, where he also went on the campaign attack. the president mocked the republican field's resistance to alternative energy. >> lately we've heard a lot of professional politicians, a lot of the folks who are, you know, running for a certain office who shall go unnamed, they have been talking down new sources of energy. if some